// Problem: 
// Contest: 
// URL: 
// Memory Limit: 
// Time Limit: 
// #pragma GCC optimize("Ofast")
// #pragma GCC optimize("unroll-loops")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")
#include<bits/stdc++.h>
using namespace std;
#define int long long
inline int read(){
	int s=0,w=1;
	char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')w=-1;ch=getchar();}
	while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
	return s*w;
}
int f=0,i;
char c;
signed main()
{
	for (;;i++)
	{
		c=getchar();
		if (c=='(') f++;
		if (c==')') f--;
		if (f<0) {printf ("NO");return 0;}
		if (c=='@') {if (!f) printf ("YES");else printf ("NO");return 0;}
	}
	return 0;
}
